Backpressure protection control method based on DCS (Distributed control system) system

The invention provides a backpressure protection control method based on a DCS (Distributed control system) system. The method comprises the following steps of: obtaining the current running power and the current backpressure value of a 300MW high backpressure unit, and obtaining the current electric power of the system by calculation according to a fuzzy control formula based on backpressure protection margin; and according to the current electric power, sending a power adjusting command to the 300MW high backpressure unit through the DCS system to adjust the current electric power. The current electric power of the system is obtained by the current running power and the current backpressure value, and the corresponding adjusting is made by the DCS system, so that the safe and economic running of the 300MW high backpressure unit in a high backpressure running state is ensured.